Response to Tyrosine Kinase Inhibitors in Patients with BCR-ABL1 Positive Chronic Myeloid Leukemia; 20 Years’ Experience at Patan Hospital, Nepal

Chronic Myeloid Leukemia (CML) is characterized by the BCR-ABL1 fusion gene and has seen improved outcomes due to tyrosine kinase inhibitors (TKIs). Imatinib, the primary therapy at Patan Hospital, Nepal, was introduced through the Max Access Program in 2003.

This retrospective analysis included 431 CML patients treated between March 2003 and April 2023. Demographic data, TKI regimens, treatment response, mutation analysis, and survival rates were reviewed.

Over 20 years at Patan Hospital, Nepal, 431 patients with BCR-ABL1 positive Chronic Myeloid Leukemia (CML) were primarily treated with imatinib through the Max Access Program. The median patient age was 41 years, with 66.8% male, and 98.4% presented in the chronic phase. Initial therapy involved imatinib in 99.1% of cases, though 24.6% switched to second- or third-generation TKIs due to resistance or intolerance. Molecular response showed 64.7% achieved optimal response, 11.6% suboptimal, and 14.6% treatment failure. Mutation analysis in 213 patients found 27.3% had mutations, most commonly T315I, managed with ponatinib. Overall survival was 89.1%, comparable to developed nations. Despite eligibility, only 7.2% entered treatment-free remission, hindered by financial, geographic, and monitoring barriers. This study demonstrates that TKIs greatly improve CML outcomes in resource-limited settings, though enhanced access to mutation testing and newer therapies is essential for further advancements.

TKI therapy, primarily with imatinib, has resulted in high response and survival rates among CML patients in Nepal, demonstrating outcomes comparable to global standards. Challenges remain regarding access to advanced mutation analysis and TFR. Expanded access to newer TKIs and diagnostics will further improve outcomes for patients in resource-limited settings.